Introduction

Twist Drills are the most common cutter type in the CNC arsenal, and they’re most commonly held in the machine tool via a drill chuck.  They can also be held in an ER collet chuck and by various other methods.  In this article, we’ll go through all this and show you how to get the best performance from your tool holding solution when it comes to twist drills.

Drill Chuck Types

There are commonly two types of drill chucks–Jacobs Chucks and Keyless Drill Chucks.

Jacobs Chuck (Chuck Key Style)

jacobs chuck

Jacobs chucks require a key to operate:

Drill Chuck Key

Keyless Drill Chuck (Albrecht)

Keyless Drill Chucks were invented in 1908 by the firm Albrecht, and are often referred to as Albrecht chucks.  They’re often preferred to Jacobs chucks because no key or wrench is needed.  A simple twist of the body tightens the chuck firmly:

keyless drill chuck albrecht

Drill Chuck Sizes

drill chuck sizes

Image courtesy of micro-machine-shop

Drill chucks come in a great variety of sizes from small to large.

Jacobs Chuck Sizes

Courtesy of Jacobs

Keyless Chuck Sizes

Keyless Drill Chuck Sizes, courtesy of Royal Products

Mini Drill Chucks, Pin Chucks, and Sensitive Drill Feeds

When drilling small holes, sometimes special chucks and accessories may be required.

The sensitive drill feed is an arbor with spring-loaded extension that can be used to hand feed delicate small twist drills with a smaller chuck:

sensitive drill feed mini chuck adapter

Sensitive Feeds are useful on manual mills and drill presses, but are seldom used with CNC where exact feeds are easily programmed.

Drill Chucks vs Collet Chucks

Drill Chucks have a number of advantages over collet chucks:

  • The drill chuck holds a much wider range of twist drill shank diameters.
  • Gripping forces of drill chucks are concentrated on three points and can be much higher than for collet chucks.

In general, if you have a well-made drill chuck, it should be as accurate as a collet chuck and will be more versatile as well as gripping the twist drill more tightly.

Mount a Drill Chuck to Stay on its Taper

I prefer to shrink fit my chucks onto their tapers.  I put the chuck in the oven at just under 200 degrees and the arbor in the freezer.  After 10-15 minutes, tap them sharply together.  The temperature difference ensures a tighter fit.

Remove a Drill Chuck

If your drill chuck is mounted on a machine taper, then you’ll use a drill chuck removal wedge to remove it:

drill chuck removal wedge

The wedge goes between top of chuck and the flange on the taper to force the two apart.  Instructables has a good article on how to approach iit.

Make sure your chuck isn’t threaded on, as a wedge will damage a threaded drill chuck installation.

Handy Chuck Key Holder

It’s hard to see in this photo, but I use a triangular welder’s magnet to hold my chuck key to my drill press so it’s always there:

 

Like what you read on CNCCookbook?

Join 100,000+ CNC'ers!  Get our latest blog posts delivered straight to your email inbox once a week for free. Plus, we’ll give you access to some great CNC reference materials including:

  • Our Big List of over 200 CNC Tips and Techniques
  • Our Free GCode Programming Basics Course
  • And more!

Just enter your name and email address below:

Full Name
Email *
100% Privacy: We will never Spam you!

Total Guide to Drill Chucks and Holding Twist Drills
4.7 (93.33%) 3 votes

 

Do you want to be a better CNC'er in 37 Seconds?

Get Better Tool Life, Surface Finish, and Material Removal Rates Fast.

It's that easy. You can install and get results in a matter of minutes.

 

Start Now, It's Free!

Home

Software

  GW Calculator

  GW Editor

  Gearotic

  Conversational

  Deals and Steals

CNC Blog

  Software

  Techniques

  Beginner

  Cool

  Projects

 

Cookbooks

     Feeds and Speeds

     G-Code Tutorial

     CNC Machining & Manufacturing

     DIY CNC Cookbook

     CNC Dictionary

CNC Projects

Resources

     Machinist's Search

     Videos

     Online Groups

     Individuals

     Reference Data

     Books

     CNC Dictionary

     Suppliers

     Tool Brands

Workshop

     Hall of Fame

     Organization: Soon!

 

About

     Customers

     Partners

     Our History

     Privacy Policy

 
All material © 2017, CNCCookbook, Inc.

Pin It on Pinterest

Share This